1. Technical Field
The present invention relates to an apparatus and a method suppressing interference of a signal received in a reverse link in a communication system in a closed space such as a building.
2. Related Art
Typically, a mobile communication system installed in a closed space such as a building (referred to hereinafter as “in-building mobile communication system”) needs a plurality of small repeaters and antennas.
A code division multiple access (CDMA) in-building mobile communication system can be used to facilitate communications between mobile telephones, for example. In such an in-building mobile communication system, a large number of small repeaters can be installed. Each of these repeaters can have an antenna for transmitting signals and for receiving signals.
In the communication system that has the large number of repeaters for transmitting and receiving signals, however, there can be a problem of increased reception interference of the reverse link in proportion to the number of the antennas.
An exemplar of a recent effort in the art includes a paper by Howard H. Xia et al. entitled “A CDMA-Distributed Antenna System for In-Building Personal Communications Services” published in the Institute of Electrical and Electronics Engineers (IEEE) Journal on Selected Areas in Communications, Vol. 14, No. 4, May 1996, pp. 644-650.
While this recent effort may provide advantages, I note that it fails to adequately provide an apparatus and method for efficiently and conveniently suppressing interference of reverse link in in-building mobile communication systems.